This invention relates to a leaf wetness emulator, that is, a device that provides a model of the wetness of plant leaves.
Various types of leaf wetness emulators have been developed to provide a model of the wetness of plant leaves in a particular environment or locale. These emulators are used, for example, to provide input signals for computer programs for plant disease forecasting and for crop management.
One type of leaf wetness emulator involves clip electrodes secured to plant leaves. While this type of emulator has improved accuracy and correlation to actual leaf surface wetness, the electrodes were easily dislodged from the leaves. Moreover, the electrodes tended to pull the leaves on which they were placed from the plants. Examples of other types of prior leaf wetness emulators include a bifilar coil whose windings can be bridged by sufficiently large water droplets, which changes the coil's electrical properties; and a network of parallel conductors printed on a flat epoxy glass substrate, in which adjacent conductors can be bridged by sufficiently large water droplets, which changes the network's electrical properties. It has generally been difficult to correlate these types of prior emulators with the wetness of leaf surfaces in the surrounding environment. Thus these types of emulators can be unreliable.
Thus, the art has lacked a leaf wetness emulator that can reliably provide a signal that accurately correlates to leaf wetness, without need for physical connection to plant leaves.